The invention relates to a pressure pick-off for generating electrical signals of the type of the main claim. Semiconductor pressure pick-off device with integrated piezoresistive resistor bridge are known in which the sensor elements are mounted in the edge area of a membrane made from a silicon semiconductor by means of spark erosion, etching or other method and which closes a reference pressure chamber against the medium being under pressure (U.S. Pat. No. 4,079,508). The reference pressure chamber is closed under a vacuum for measuring of absolute pressures. In such and similar pressure pick-off devices which have a reference pressure chamber being filled with precious gas or being under a vacuum for pressure measuring the signals which are transmitted from the sensor elements or from a pressure switch are falsified as soon as the reference pressure chamber becomes leaky. A leakage in the reference pressure chamber in such pressure pick-off devices can only be recognized by an aftermeasuring during the maintenance of the sensors. The subject solution tries to monitor the tightness of the reference pressure chamber during the use of the pressure pick-off with connected evaluation circuit.